Self-compensating bed scale system for removable components

ABSTRACT

A patient support apparatus includes detectors and a controller operable to automatically update a tare weight for use in determining a true patient weight. The detectors are configured to produce signals indicating a presence or absence of a corresponding removable component. The controller is configured to determine weights of each and every removable component on the patient support apparatus and store each weight in a memory. The controller is further configured to receive the signals produced by the detectors and detect any addition or removal of removable components of the patient support apparatus, update the tare weight, and determine a weight of a patient being supported on the patient support apparatus.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit, under 35 U.S.C. § 119(e), ofU.S. Provisional Application No. 62/153,128, filed Apr. 27, 2015, whichis hereby incorporated by reference herein.

BACKGROUND

The present disclosure is related to a patient support apparatus thatincludes a control system for automatically calculating a true weight ofa patient placed on the patient support apparatus. More specifically,the present disclosure is directed to a patient support apparatus havingremovable components such as headboard, footboard, siderail, infusionsupport, drainage container, or urinal container.

In a care facility, such as a hospital or a nursing home, patients areoften placed on patient support apparatuses for an extended period oftime. Patients who are positioned on the patient support apparatus forextended periods have an increased risk of developing certaincomplications or injuries, such as certain skin condition that mayincrease the potential of nosocomial pressure ulcers occurring. In aneffort to mitigate or prevent such complications or injuries, somepatient support apparatuses use load information gathered from anintegrated scale system to derive pressure set points for a dynamicsupport surface, which continually redistributes the pressure of thedynamic support surface against the patient's skin. However, the weightattributable to the added or removed removable components while thepatient remains on a patient support apparatus often causes errors incalculating the true weight of the patient, which in turn can lead tonon-optimal pressure set points being derived from dynamic supportsurfaces.

In addition, caregivers often monitor the weight of a patient who is ina care facility to diagnose and treat certain medical conditions. Forexample, some caregivers closely monitor a patient's weight loss orweight gain throughout a course of treatment to determine, for example,whether the patient is retaining water. To facilitate making thosedeterminations, some caregivers use an amount of weight calculated bythe patient support apparatus upon which the patient is being supported.The weight attributable to added or removed removable components whilethe patient remains on the patient support apparatus may cause incorrectweight readings and result in incorrect diagnosis or treatment tocertain medical conditions.

SUMMARY

The present application discloses one or more of the features recited inthe appended claims and/or the following features which, alone or in anycombination, may comprise patentable subject matter:

According to a first aspect of the present disclosure, a patient supportapparatus comprises a patient support, a plurality of load cells, aplurality of detectors, and a controller. The plurality of load cellssupports the patient support. Each load cell is configured to produce asignal indicative of an amount of weight on that load cell. Eachdetector is configured to produce a signal indicative of a presence of acorresponding removable component. The controller is in communicationwith the plurality of the load cells and the plurality of detectors. Thecontroller is configured to receive the signal produced by each of theload cells and the detectors. The controller is also configured todetermine a weight of the patient being supported on the patientsupport. The controller is further configured to detect, subsequent todetermining the weight of the patient, any subsequent removal oraddition of one or more of the removable components of the patientsupport apparatus based on the signals produced by the plurality ofdetectors. The controller is still yet configured to update the weightof the patient being supported on the patient support considering theeffect of the removal or addition of the one or more of the removablecomponents.

In some embodiments, the controller may be further configured todetermine an initial tare weight of the empty patient support apparatus,and determine whether the patient support is supporting a patient as afunction of the signals produced by the plurality of load cells.

In some embodiments, the controller may be further configured todetermine whether the patient support is supporting the patient bydetermining a current occupancy state of the patient support apparatus.The current occupancy state of the patient support apparatus maycomprise at least one of an occupied state and an unoccupied state. Theoccupied state may be indicated when the patient support is determinedto be supporting the patient and the unoccupied state may be indicatedwhen the patient support is determined not to be supporting the patient.

In some embodiments, the controller is further configured to thecontroller may be further configured to automatically update the tareweight of the patient support apparatus.

In some embodiments, the tare weight of the patient support apparatusmay include the total amount of weight of the empty patient supportapparatus being compensated for a first amount of weight and secondamount of weight, the first amount of weight corresponding to the weightof the subsequently added removable components, and the second amount ofweight corresponding to the weight of the subsequently removed removablecomponents of the patient support apparatus.

In some embodiments, updating the tare weight in response to detectingthe addition or removal of the removable components may include updatingthe tare weight in response to (i) determining that the patient supportis no longer supporting the patient, (ii) storing the removablecomponents initially detected on the empty patient support apparatus,(iii) storing total weight of the empty patient support apparatus as afunction of initial tare weight, and (iv) updating the tare weight bysupplementing the weight of the removable components added to thepatient support apparatus or by offsetting the weight of the removablecomponents removed from the patient support apparatus in response tosignals received from the plurality of detectors.

In some embodiments, the controller may be further configured todetermine a normalized amount of weight of each removable component ofthe patient support apparatus as a function of the signals produced bythe plurality of load cells. The controller may be still furtherconfigured to detect the removable components currently attached to thepatient support apparatus in response to detecting a presence or absenceof the corresponding removable component by the plurality of detectors.Yet further, the controller may be configured to determine and store atotal weight of the removable components currently attached to thepatient support apparatus. The controller may be still furtherconfigured to detect any subsequent addition or removal of the removablecomponents from the patient support apparatus.

In some embodiments the controller may be further configured to set aninitial occupancy state of the patient support apparatus to anunoccupied state. The controller may determine a normalized amount ofweight on the plurality of load cells as a function of the signalsproduced by the plurality of load cells. The controller may also set thecurrent occupancy state of the patient support apparatus to the occupiedstate in response to the normalized amount of weight on the plurality ofload cells satisfying an occupied condition, the occupied conditiondefining a first normalized threshold value for which the normalizedamount of weight on the plurality of load cells must exceed. Thecontroller may still yet be configured to set the current occupancystate of the patient support apparatus to the unoccupied state inresponse to the normalized amount of weight on the plurality of loadcells satisfying an unoccupied condition, the unoccupied conditiondefining a second normalized threshold value for which the normalizedamount of weight on the plurality of load cells must be below.

In some embodiments, the controller is further configured to determine,in response to determining that the patient support is no longersupporting the patient, a total amount of weight of the empty patientsupport apparatus as a function of signals received from the pluralityof load cells. The controller may also be configured to set and storethe total amount of weight of the empty patient support apparatus as aninitial tare weight of the patient support apparatus.

In some embodiments, the total amount of weight of the empty patientsupport apparatus may include the amount of weight on the plurality ofload cells of the empty patient support apparatus. The amount of weightof the empty patient support apparatus may also include the total amountof weight of the removable components currently attached to the emptypatient support apparatus.

In some embodiments, updating a weight of the patient may include (i)determining the empty patient support apparatus as a function of signalsreceived from the plurality of load cells, (ii) determining the presenceor absence of removable components of the patient support apparatus inresponse to the signals received from the plurality of detectors, (iii)determining the tare weight of the patient support apparatus, and (iv)offsetting the updated tare weight from the total amount of weight ofthe patient support apparatus.

In some embodiments, the controller may comprise a processor; and atleast one machine-readable storage medium including a plurality ofinstructions. The instructions may, in response to being executed by theprocessor, automatically determine the patient weight based on thesignals from the load cells and the sensors.

In some embodiments, determining the presence or absence of removablecomponents of the patient support apparatus may include detecting thesignal produced by one or more corresponding detectors associated witheach removable component.

In some embodiments, the removable component of the patient supportapparatus may include a headboard, a footboard, a siderail, an infusionsupport, a drainage container, or a urinal container.

In some embodiments, the patient support apparatus may further include auser interface that includes a graphical display and the presence orabsence of any one of the removable components may be indicated by anicon representation of the patient support apparatus.

In some embodiments, the information regarding the presence or absenceof removable components may be transmitted to a graphical display remotefrom the patient support apparatus.

In some embodiments, the remote graphical display may be a mobilecomputing device associated with a particular caregiver.

According to a second aspect of the present disclosure, a method ofdetermining and displaying a patient weight on a patient supportapparatus includes receiving information from a plurality of load cellsconfigured to support the patient, each load cell configured to producea signal indicative of an amount of weight on that load cell. The methodalso includes receiving information from a plurality of detectors, eachdetector configured to produce a signal indicative of a presence of acorresponding removable component of the patient support apparatus. Themethod further includes determining, from the information, a weight ofthe patient being supported on the patient support. The method alsoincludes detecting, subsequent to determining the weight of the patient,any subsequent removal or addition of one or more of the removablecomponents of the patient support apparatus based on the signalsproduced by the plurality of detectors. The method still furtherincludes updating the weight of the patient being supported on thepatient support considering the effect of the removal or addition of theone or more of the removable components.

In embodiments, the method may further include determining an initialtare weight of the empty patient support apparatus and determiningwhether the patient support is supporting a patient as a function of thesignals produced by the plurality of load cells.

In embodiments, the method may further include determining whether thepatient support is supporting the patient comprises determining acurrent occupancy state of the patient support apparatus, wherein thecurrent occupancy state of the patient support apparatus comprises atleast one of an occupied state and an unoccupied state, the occupiedstate being indicated when the patient support is determined to besupporting the patient and the unoccupied state being indicated when thepatient support is determined not to be supporting the patient.

In embodiments, the method may further include automatically updatingthe tare weight of the patient support apparatus.

In embodiments, the tare weight of the patient support apparatus mayinclude the total amount of weight of the empty patient supportapparatus being compensated for a first amount of weight and secondamount of weight, the first amount of weight corresponding to the weightof the subsequently added removable components, and the second amount ofweight corresponding to the weight of the subsequently removed removablecomponents of the patient support apparatus.

In embodiments, the method may further include updating a tare weight inresponse to detecting the addition or removal of the removablecomponents comprises updating the tare weight in response to (i)determining that the patient support is no longer supporting thepatient, (ii) storing the removable components initially detected on theempty patient support apparatus, (iii) storing total weight of the emptypatient support apparatus as a function of initial tare weight, and (iv)updating the tare weight by supplementing the weight of the removablecomponents added to the patient support apparatus or by offsetting theweight of the removable components removed from the patient supportapparatus in response to signals received from the plurality ofdetectors.

In embodiments, the method may further include determining a normalizedamount of weight of each removable component of the patient supportapparatus as a function of the signals produced by the plurality of loadcells, detecting the removable components currently attached to thepatient support apparatus in response to detecting a presence or absenceof the corresponding removable component by the plurality of detectors,determining and storing a total weight of the removable componentscurrently attached to the patient support apparatus, and detecting anysubsequent addition or removal of the removable components from thepatient support apparatus.

In embodiments, the method may further include determining the presenceor absence of removable components of the patient support apparatuscomprises detecting the signal produced by one or more correspondingdetectors associated with each removable component.

In embodiments, a removable component of the patient support apparatusmay include a headboard, footboard, siderail, infusion support, drainagecontainer, or a urinal container.

In embodiments, the method may further include graphically indicatingthe presence or absence of any one of the removable components by anicon representation of the patient support apparatus.

According to a third aspect of the present disclosure, a method ofdetermining the weight of one or more removable components of a patientsupport apparatus that includes a plurality of load cells comprisesdetermining an initial tare weight for the patient support apparatus.The method further includes prompting a user to add a first removablecomponent to the patient support apparatus. The method further includesdetecting the presence of the removable component by a sensor associatedwith the removable component. The method still further includesdetermining, using the load cells, the weight of the removablecomponent.

In embodiments, the method may further include storing the weight of thefirst removable component in a memory device.

In embodiments, the method may further include determining an updatedtare weight based on the added weight of the first removable component.

In embodiments, the method may further include storing the updated tareweight in a memory device.

In embodiments, the method may further include prompting a user to add asecond removable component to the patient support apparatus, detectingthe presence of the second removable component based on a signalassociated with the second removable component, and determining, usingthe load cells, the weight of the second removable component.

In embodiments, the method may further include storing the weight of thesecond removable component in a memory device.

In embodiments, the method may further include determining an updatedtare weight based on the added weight of the second removable component.

In embodiments, the method may further include storing the updated tareweight in a memory device.

In embodiments, the method may further include monitoring the sensorassociated with the first removable component and the sensor associatedwith the second removable component to determine if either the first orsecond removable component is removed, and, if a removable component isdetected to be removed, updating the tare weight to account for theremoval of the weight of the component that has been removed.

According to a fourth aspect of the present disclosure, a patientsupport apparatus includes a patient support, a plurality of load cells,a plurality of detectors, and a controller. The plurality of load cellssupports the patient support. Each load cell is configured to produce asignal indicative of an amount of weight on that load cell. Eachdetector is configured to produce a signal indicative of a presence of acorresponding removable component. The controller is in communicationwith the plurality of load cells and the plurality of detectors. Thecontroller is configured to receive the signal produced by each of theplurality of load cells and each of the plurality of detectors,determine an initial tare weight of the empty patient support apparatus,determine whether the patient support is supporting a patient as afunction of the signals produced by the plurality of load cells, anddetermine the weight of the patient being supported on the patientsupport. The controller is further configured to detect, subsequent todetermining the weight of the patient, any subsequent removal oraddition of the removable components of the patient support apparatus,update the tare weight of the patient support apparatus, and update theweight of the patient being supported on the patient support.

In some embodiments, the controller is configured to determine thenormalized amount of weight of each removable component of the patientsupport apparatus as a function of the signals produced by the pluralityof load cells. The controller is further configured to detect theremovable component currently attached to the patient support apparatusin response to detecting a presence or absence of the correspondingremovable component by the plurality of detectors, determine and storethe total weight of the removable components currently attached to thepatient support apparatus, and detect any subsequent removal or additionof the removable components on the patient support apparatus.

In some embodiments, determining whether the patient support issupporting the patient may further include determining a currentoccupancy state of the patient support apparatus.

In some embodiments, the current occupancy state of the patient supportapparatus may further include at least one of an occupied state and anunoccupied state. The occupied state is indicated when the patientsupport is determined to be supporting the patient and the unoccupiedstate is indicated when the patient support is determined not to besupporting the patient.

In some embodiments, the controller is further configured to set aninitial occupancy state of the patient support apparatus to theunoccupied state and determine a normalized amount of weight on theplurality of load cells as a function of the signals produced by theplurality of load cells. The controller is further configured to set thecurrent occupancy state of the patient support apparatus to the occupiedstate in response to the normalized amount of weight on the plurality ofload cells satisfying an occupied condition. The occupied conditiondefines a first normalized threshold value for which the normalizedamount of weight on the plurality of load cells must exceed. Thecontroller may further be configured to set the current occupancy stateof the patient support apparatus to the unoccupied state in response tothe normalized amount of weight on the plurality of load cellssatisfying an unoccupied condition. The unoccupied condition defines asecond normalized threshold value for which the normalized amount ofweight on the plurality of load cells must be below.

In some embodiments, the controller is further configured to determine,in response to determining that the patient support is no longersupporting the patient, a total amount of weight of the empty patientsupport apparatus as a function of signals received from the pluralityof load cells, and set and store the total amount of weight of the emptypatient support apparatus as an initial tare weight of the patientsupport apparatus.

In some embodiments, the total amount of weight of the empty patientsupport apparatus comprises the amount of weight on the plurality ofload cells of the non-patient support apparatus. The amount of weight ofthe non-patient support apparatus may further include the total amountof weight of the removable components currently attached to the patientsupport apparatus.

In some embodiments, the tare weight of the patient support apparatuscomprises the total amount of weight of the empty patient supportapparatus being compensated for a first amount of weight and secondamount of weight. The first amount of weight corresponds to the weightof the subsequently added removable component and the second amount ofweight corresponds to the weight of the subsequently removed removablecomponents of the patient support apparatus.

In some embodiments, updating the tare weight of the patient supportapparatus in response to detecting the addition or removal of theremovable components comprises updating the tare weight in response to(i) determining that the patient support is no longer supporting thepatient, (ii) storing the removable components initially detected on theempty patient support apparatus, (ii) storing total weight of the emptypatient support apparatus as a function of initial tare weight, and (iv)updating the tare weight by supplementing the weight of the removablecomponents added to the patient support apparatus or by offsetting theweight of the removable components removed from the patient supportapparatus in response to signals received from the plurality ofdetectors.

In some embodiments, updating a weight of the patient may furtherinclude (i) determining the empty patient support apparatus as afunction of signals received from the plurality of load cells, (ii)determining the presence or absence of removable components of thepatient support apparatus based on signals received from the pluralityof detectors, (iii) determining the updated tare weight of the patientsupport apparatus, and (iv) offsetting the updated tare weight from thetotal weight of the patient support apparatus.

In a fifth aspect of the present disclosure, a patient support apparatusincludes a processor and at least one machine-readable storage medium.The at least one machine-readable storage medium includes a plurality ofinstructions, that in response to being executed by the processor,result in the patient support apparatus receiving, (i) a signal producedby each of a plurality of load cells supporting a patient support of thepatient support apparatus, the signal produced by each load cellindicating an amount of weight on that load cell, and (ii) a signalproduced by each of the plurality of detectors associated with eachremovable components of the patient support apparatus, the signalproduced by each detector indicating the presence or absence of theremovable component. The at least one machine-readable storage mediumfurther includes a plurality of instructions, that in response to beingexecuted by the processor, result in the patient support apparatusdetermining a tare weight of the patient support apparatus bycompensating the weight indicated by the load cells, determining aweight of a patient being supported on the patient support by offsettingthe tare weight from the weight indicated by the load cells, detecting,subsequent to determining the weight of the patient, further changes inthe tare weight of the patient support apparatus, and updating theweight of the patient by updating the tare weight of the patient supportapparatus.

In some embodiments, determining the presence or absence of removablecomponents of the patient support apparatus comprises detecting thesignal produced by one or more corresponding detectors associated witheach removable component.

In some embodiments, the removable component of the patient supportapparatus may further include headboard, footboard, siderail, infusionsupport, drainage container, or urinal container.

In some embodiments, the tare weight of the patient support apparatuscomprises a current weight of the empty patient support apparatusincluding a current weight of the removable components that aredetected.

In some embodiments, each load cell is configured to produce a signalindicative of an amount of weight on that load cell and the plurality ofload cells is configured to produce a signal indicative of a totalamount of weight on the patient support apparatus.

In some embodiments, the plurality of load cells determines the weightof the empty patient support apparatus. The weight of the empty patientsupport apparatus corresponds to the weight of non-patient items placedon the plurality of load cells on the patient support, including thecurrently attached removable components of the patient supportapparatus.

In some embodiments, the detectors are configured to determine thepresence or absence of removable components of the patient supportapparatus and produce corresponding signals to the processor. Theexamples of the detecting mechanism include hall-effect mechanisms orswitch-type mechanisms.

In some embodiments, the controller is configure to determine, inresponse to determining the patient support is no longer supporting thepatient, the weight of the empty patient support apparatus as a functionof signals received from the plurality of load cells, set and store theweight of the empty patient support apparatus as an initial tare weightof the patient support apparatus, detect, subsequent to determining theweight of the empty patient support apparatus, any subsequent removal oraddition of removable components of the patient support apparatus as afunction of signals received from the plurality of detectors, update thetare weight by assessing the weight of the empty patient supportapparatus and the weight of currently attached removable components, anddetermine the weight of the patient by offsetting the tare weight.

In a sixth aspect of the preset disclosure, a method for determining andstoring weights of each and every removable component on a patientsupport apparatus may further include the step of determining, on acontroller of the patient support apparatus, whether a historical weightdata of each and every removable components is stored in a memory of thepatient support apparatus. The method further includes the step ofdetecting, on the controller, subsequent to loading each removablecomponent on the patient support apparatus, the presence of eachremovable component in response to receiving a signal produced by one ormore corresponding detectors. The method further includes the steps ofdetermining an amount of weight of each and every removable component inresponse to receiving a signal produced by a plurality of load cells andstoring the amount of weight of each and every removable component inthe memory of the patient support apparatus.

In some embodiments, detecting each removable component loaded on thepatient support apparatus may further include the step of loading eachremovable component into the corresponding mounting sockets of thepatient support apparatus. Each mounting socket comprises one or moredetectors that are configured to determine the presence or absence ofremovable components of the patient support apparatus and producecorresponding signals to the processor.

In a seventh aspect of the present disclosure, a method for adjusting atare weight includes the steps of receiving, on a controller of apatient support apparatus, an initial tare weight of the patient supportapparatus, detecting, on the controller, an addition or removal of anyremovable components on the patient support apparatus in response toreceiving a signal produced by each of a plurality of detectorsindicating a presence or absence of a corresponding removable component,determining and compensating, on the controller, an amount of weight ofthe removable components that has been added or removed from the patientsupport apparatus, and updating, on the controller, the tare weight ofthe patient support apparatus.

In some embodiments, compensating the amount of weight of the removablecomponents comprises a current total amount of weight on the pluralityof load cells being compensated for a first amount of weight and asecond amount of weight. The first amount of weight corresponds to theweight of the removable components added to the patient supportapparatus in response to signals received from the plurality ofdetectors, and the second amount of weight corresponds to the weight ofthe removable components removed from the patient support apparatus inresponse to signals received from the plurality of detectors.

In some embodiments, the method for adjusting a tare weight furtherincludes receiving, on the controller of a patient support apparatus, asignal produced by each of a plurality of load cells supporting apatient support, the signal produced by each load cell indicating anamount of weight on that load cell. The method may further include thestep of determining, on the controller, whether the patient support ofthe patient support apparatus is supporting a patient as a function ofthe signals produced by the plurality of load cells. The method mayfurther include the steps of determining, on the controller, subsequentto determining that the patient support apparatus is not supporting apatient, an amount of weight of the empty patient support apparatus, andstoring, on the controller, the amount of weight of the empty patientsupport apparatus as an initial tare weight of the patient supportapparatus.

In some embodiments, determining whether the patient support issupporting a patient may further include the steps of determining acurrent occupancy state of the patient support apparatus. The currentoccupancy state of the patient support apparatus comprises at least oneof an occupied state and an unoccupied state. The occupied state isindicated when the patient support is determined to be supporting thepatient and the unoccupied state is indicated when the patient supportis determined not to be supporting the patient.

Additional features, which alone or in combination with any otherfeature(s), including those listed above and those listed in the claims,may comprise patentable subject matter and will become apparent to thoseskilled in the art upon consideration of the following detaileddescription of illustrative embodiments exemplifying the best mode ofcarrying out the invention as presently perceived.

BRIEF DESCRIPTION OF THE DRAWINGS

The detailed description particularly refers to the accompanying figuresin which:

FIG. 1 is a perspective view from the foot end on the patient's left ofa patient support apparatus;

FIG. 2 is a perspective view of the patient support apparatus of FIG. 1with a siderail detached from the patient support apparatus;

FIG. 3 is a perspective view from the head end on the patient's left ofthe patient support apparatus of FIG. 1, wherein the patient supportapparatus further includes a patient helper attached thereto;

FIG. 4 is a block diagram of a portion of the electrical system of thepatient support apparatus of FIG. 1 used to determine a tare weight ofthe patient support apparatus;

FIG. 5 is a block diagram of the positions of a number of load cells andmounting sockets relative to the patient support apparatus of FIG. 1;

FIG. 6 is a cross-section of a first embodiment of the mounting socketin the upper frame of the patient support apparatus of FIG. 1 with anembedded hall-effect mechanism detector;

FIG. 7 is a cross-section of a second embodiment of a mounting socket inthe upper frame of the patient support apparatus of FIG. 1 with anembedded switch-type mechanism detector FIG. 7 showing a portion of asiderail in a first position;

FIG. 8 is a cross-section of the second embodiment of the mountingsocket in the upper frame of the patient support apparatus of FIG. 1with an embedded switch-type mechanism detector FIG. 7 showing theportion of the sidereal in a second position activating the switch;

FIG. 9 is a cross-section of a third embodiment of the mounting socketin the upper frame of the patient support apparatus of FIG. 1 with ahall-effect mechanism detector positioned at the bottom end of themounting socket;

FIG. 10 is a cross-section of a fourth embodiment of a mounting socketin the upper frame of the patient support apparatus of FIG. 1 with aswitch-type mechanism detector at the bottom end of the mounting socketFIG. 10 showing a portion of a siderail in a first position;

FIG. 11 is a cross-section of the fourth embodiment of the mountingsocket in the upper frame of the patient support apparatus of FIG. 1with a switch-type mechanism detector at the bottom end of the mountingsocket FIG. 10 showing the portion of the sidereal in a second positionactivating the switch;

FIG. 12 is a perspective view of a siderail of the patient supportapparatus of FIG. 1;

FIG. 13 is a flow chart showing a routine process performed by theprocessor of the patient support apparatus of FIG. 1 to determine thetrue patient weight;

FIG. 14 is a flow chart showing a sub-routine process for determiningand storing each and every removable component of the patient supportapparatus that forms one part of the routine process of FIG. 13;

FIG. 15 is a state diagram illustrating one embodiment of a controlsub-routine for determining whether a patient is being supported by thepatient support apparatus that forms one part of the routine process ofFIG. 13;

FIG. 16 is a flow chart showing a sub-routine process for initializing atare weight that forms one part of the routine process of FIG. 13;

FIG. 17 is a flow chart showing a sub-routine process for determiningand offsetting the tare weight that forms one part of the routineprocess of FIG. 13;

FIG. 18 is a flow chart showing a sub-routine process for updating atare weight as a function of historical weight information that formsone part of the routine of FIG. 17;

FIG. 19 is a depiction of a particular embodiment of a user interfacescreen of the patient support apparatus of FIG. 1, the user interfacescreen depicting a status of subsystems of the patient support apparatusincluding a depiction of the barriers present on the patient supportapparatus; and

FIG. 20 is a depiction of the user interface similar to FIG. 19, withFIG. 20 showing that a siderail that has been removed from the patientsupport apparatus no longer appears on the user interface.

DETAILED DESCRIPTION

An illustrative patient support apparatus embodied as a hospital bed 10is shown in FIG. 1. The patient support apparatus 10 of FIG. 1 has anauto-tare function, which detects and compensates for any addition orremoval of one or more removable components 14 that affect determinationof the true patient weight. The patient support apparatus 10 has anumber of removable components 14 attached to a fixed bed frame 16 asshown in FIG. 1. The fixed bed frame 16 includes a base frame 26 withcasters 38 and an upper frame 28. The upper frame 28 includes a numberof mattress support sections that support a therapy surface 30. Theillustrative patient support apparatus 10 has a user interface 70 thatincludes an input panel or control panel 56 that is affixed to thefootboard 20 of the patient support apparatus 10. The user interface 70is coupled to the controller 410 as shown in FIG. 4. In addition, theuser interface 70 includes a graphical user interface 72 that includes atouchscreen panel that allows a user to modify various subsystems of thepatient support apparatus 10. The graphical user interface 72 alsoprovides graphical real-time status indications relative to the patientsupport apparatus 10 to the user. As will be discussed in further detailbelow, this real-time status provides important feedback to the user orcaregiver as the operational parameters of the patient support apparatus10 are modified.

As shown in FIG. 3, all removable components 14, including a headboard18, a footboard 20, siderails 22, and a patient helper 24, are in anattached position. The removable component 14 has vertically projectedprongs 15 that are configured to fit into mounting sockets 52 which arelocated along the edges of the upper frame 28 as shown in FIG. 2. Eachremovable component 14 is removable from the patient support apparatus10 to provide easier access for the patient and caregivers. For example,the siderail 22 is removed by sliding a rail latch 40 toward an unlockposition and lifting up the siderail 22 from the mounting sockets 52 asshown in FIG. 2. To attach the siderail 22 back to the patient supportapparatus 10, align and mount the prongs 15 of the siderail 22 into thecorresponding mounting sockets 52 then slide the rail latch 40 toward alock position.

Each mounting socket 52 has one or more detectors 50. Each detector 50is configured to produce a signal indicative of the presence or absenceof the corresponding removable component 14. Each detector 50 detectsthe presence of the removable component 14 by detecting the prong 15 ofthe removable component 14 which is vertically projected into thecylindrical space 58 of the mounting socket 52.

In some embodiments, the mounting socket 52 has one or more embeddeddetectors 50 mounted on the surface 60 of the cylindrical space 58 ofthe mounting socket 52. In an illustrative embodiment, the mountingsocket 52 has the embedded hall-effect mechanism detector 50 as shown inFIG. 6. The embedded hall-effect mechanism detector 50 detects the prong15 of the removable component 14 when the prong 15 comes in nearproximity with the embedded hall-effect mechanism detector 50 in thecylindrical space 58 of the mounting socket 52. In other embodiments,the mounting socket 52 has the embedded switch-type mechanism detector50 as shown in FIGS. 7-8. The embedded switch-type mechanism detector 50is inactive when the corresponding removable component 14 is notattached to the patient support apparatus 10 as shown in FIG. 7. Theembedded switch-type mechanism detector 50 is activated when theembedded switch 62 is in a physical contact with the tip 13 of the prong15 of the removable component 14 as shown in FIG. 8.

In some embodiments as shown in FIGS. 9-11, each mounting socket 52 hasa detector 50 at the lower end of the cylindrical space 58 of themounting socket 52, which is horizontally parallel to the upper frame28. When the removable component 14 is attached to the patient supportapparatus 10, the tip 13 of the prong 15 of the removable component 14rests on the near surface of the detector 50. In an illustrativeembodiment, the mounting socket 52 has the hall-effect mechanismdetector 50 as shown in FIG. 9. The hall-effect mechanism detector 50detects the tip 13 of the prong 15 of the removable component 14 whenthe prong 15 comes in near proximity with the detector 50 at the lowerend of the cylindrical space 58 of the mounting socket 52. In otherembodiments, the mounting socket 52 has the switch-type mechanismdetector 50 as shown in FIGS. 10-11. The switch-type mechanism detector50 is inactive when the corresponding removable component 14 is notattached to the patient support apparatus 10 as shown in FIG. 10. Theswitch-type mechanism detector 50 is activated when the switch 62 is ina physical contact with the tip 13 of the prong 15 of the removablecomponent 14 as shown in FIG. 11.

Referring to FIG. 5, the base frame 26 supports a weigh frame 54 that ismounted via frame member 57 a and 57 b to the upper frame 28 configuredto support the therapy surface 30. A number of load cells 68 a-d arepositioned between the weigh frame 54 and the base frame 26, whereineach load cell 68 a-d is configured to produce a signal indicative of aweight supported by that load cell 68 a-d from the weigh frame 54relative to the base frame 26. In one illustrative embodiment showndiagrammatically in FIG. 4, the patient support apparatus 10 includes aweigh scale module 80 configured to automatically update a tare weightfor use in determining a true patient weight. The weigh scale module 80includes a processor module 82 that is in communication with each of theload cells 68 and detectors 50. The processor module 400 includes amicroprocessor-based controller 86 having a flash memory unit 88 and alocal random-access memory (RAM) unit 414. The local RAM unit 414 isutilized by the controller 86 to temporarily store informationcorresponding to features and functions provided by the patient supportapparatus 10. More specifically, the controller 86 is configured toadjust the tare weight of the patient support apparatus 10 based on thesignals provided by the load cells 68 and the detectors 50.

In addition, and referring to FIGS. 19 and 20, the presence or absenceof the removable components 14 is indicated graphically on thetouchscreen 72. The touchscreen 72 is divided into a main menu portion120 and a status portion 122. For example, in FIG. 19, the status ofseveral removable components 14 is indicated graphically. However, whena foot-end siderail shown in FIG. 19 and indicated by reference numeral76 is not present, the foot-end siderail is not displayed graphically asindicated in FIG. 20. This variation provides immediate feedback to acaregiver or other user of the status of the various components of thepatient support apparatus 10. In addition, a graphical representation124 of the patient support apparatus 10 shows a head section 126 in araised position and provides an indicia 128 of the head angle. Inaddition, indicia 130 in the form of animated bubbles, shows that theair fluidized portion of the surface 30 is active. The touchscreen 72also displays the current temperature 130 through indicia on thetouchscreen 72. The main menu portion 120 shows a scroll bar that hasseveral icons that allow a user to select one of several options thatmay be displayed and controlled on the status portion 122.

While the disclosed embodiment shows the presence of the removablecomponent 14, illustratively embodied as the siderail 76 as present inFIG. 19 and absent in FIG. 20, it should be understood that otherapproaches to indicating the absence of the siderail 76 may be used tosignal the caregiver or user. For example, the missing removablecomponent 14 may flash on and off, be shown in phantom or ghosting onthe display, or may be shown on the screen but separated from the bed,as examples. Still further, the display 72 may be shown on a remotedisplay 140 (seen in FIG. 4), such as a nurse station, for example, withthe indication of the presence and absence of removable components 14using the same techniques discussed above. A remote display may be awired or wireless connection with the display 140 driven by display 72,or may be a duplicate display 142 that is rebuilt at a remote locationby a separate controller that receives data regarding the status of thepatient support apparatus 10 from controller 410 and creates the remotedisplay from that data. Still further, the remote display 140 or 142 maybe presented on a mobile computing device, such as a personal digitalassistant, used by a caregiver. The presentation on the mobile computingdevice may in addition to both the local display 72, remote display 140or 142, or may be an alternative to either or all.

Referring to FIG. 14, an initial process 200 for determining the weightsof each and every removable component 14 and store the weights in thememory 84 is shown. The initial process 200 illustratively begins atdecision step 202 where the controller 86 is operable to determinewhether historical weight data of each removable component 14 is storedin a memory 84 of the patient support apparatus 10. If the controller 86determines that the historical weight data of each removable component14 does not exist in the memory 84, the initial process 200 advances todecision step 204 in which the controller 86 determines whether anyremovable components 14 are currently attached to the patient supportapparatus 10. For example, in one embodiment, the controller 86determines whether or not any removable components 14 are currentlyattached to the patient support apparatus 10 in response to receivingsignals produced by one or more detectors 50. If the controller 86determines that none of the removable components 14 are currentlyattached to the patient support apparatus 10, the initial process 200advances to step 206.

At step 206, one removable component 14 is added on the patient supportapparatus 10 at a time. When each removable component 14 is loaded intothe corresponding mounting socket 52, one or more detectors 50 detectthe presence of the particular removable component 14 and produce thesignal to the controller 86. When the controller 86 receives the signalfrom the detectors 50, the initial process 200 proceeds to step 210where the controller 86 determines which removable component 14 isdetected on the patient support apparatus 10 and stores the weight ofeach removable component 14 in the memory 84. Once the weights of eachand every removable component 14 are stored in the memory 84, theinitial process 200 proceeds to step 102 of a routine process 100.

Referring to FIG. 13, the routine process 100 for determining the truepatient weight is shown. The routine process 100 illustratively beginsat decision step 102 where the controller 86 is operable to check anoccupancy state of the patient support apparatus 10. FIG. 15 is a statediagram 600 illustrating one embodiment of the occupancy states of thepatient support apparatus 10 as determined by the controller 86. Asdescribed above, the controller 86 determines whether or not a patient36 is being supported by a support surface of the therapy surface 30 andupdates the occupancy state accordingly. In one embodiment, thecontroller 86 determines two discrete states of occupancy, an occupiedstate 602 indicative of the patient 36 being in the patient supportapparatus 10 and an unoccupied state 604 indicative of the patient 36not being in the patient support apparatus 10. It should be understoodthat while the illustrative embodiment of FIG. 15 shows two discreteoccupancy states, any number of occupancy states are contemplated bythis disclosure. For example, the controller 86 may determine that thepatient is both partially in and partially out of the patient supportapparatus 10 (e.g., the patient is sitting on the edge of the patientsupport apparatus 10) at any given point of time.

The controller 86, in one embodiment, initializes the occupancy state ofthe patient support apparatus 10 to the unoccupied state 604. Afterinitialization, the controller 86 updates the occupancy state of thepatient support apparatus 10 to the occupied state 602 in response todetermining that a normalized amount of weight on the weigh frame 54satisfies a reference occupied threshold. For example, in oneembodiment, the controller 86 updates the occupancy state of the patientsupport apparatus 10 to the occupied state 602 in response todetermining that the normalized amount of weight on the weigh frame 54meets or exceeds 31 pounds. In the illustrative embodiment, thecontroller 86 updates the occupancy state of the patient supportapparatus 10 to the occupied state 602.

After updating the occupancy state to the occupied state 602, thecontroller 86 updates the occupancy state of the patient supportapparatus 10 to the unoccupied state 604 in response to determining thatthe normalized amount of weight on the weigh frame 54 satisfies areference unoccupied threshold. For example, in the illustratedembodiment, the controller 86 updates the occupancy state of the patientsupport apparatus 10 to the unoccupied state 604 in response todetermining that the normalized amount of weight on the weigh frame 54meets or falls below 65 pounds. In the present embodiment, thecontroller 86 updates the occupancy state of the patient supportapparatus 10 to the unoccupied state 604.

Referring back to FIG. 13, if the controller 86 determines that thepatient 36 is not supported on the patient support apparatus 10, theroutine process 100 advances to step 300 in which the tare weight of theempty patient support apparatus 10 is initialized and stored. Theinitial tare weight includes the weight of the empty patient supportapparatus 10 with any removable components 14 detected on the patientsupport apparatus 10. At step 300, the controller 86 also detects anyremovable components 14 initially present on the empty patient supportapparatus 10 and stores the information in the local RAM unit 414. Afterstoring the initial tare weight, the routine process 100 advances todecision step 104 where the controller 86 is operable to determinewhether auto-tare functionality has been enabled on the patient supportapparatus 10.

If the controller 86 determines that auto-tare functionality has beenenabled on the patient support apparatus 10, the routine process 100advances to step 106 where the controller 86 is operable to check againan occupancy state of the patient support apparatus 10 to determinewhether the patient 36 is supported on the patient support apparatus 10.If the controller 86 determines that the patient 36 is now supported onthe patient support apparatus 10, the routine process 100 proceeds tostep 108 where the controller 86 captures and stores the total weight ona weigh frame 54 of the patient support apparatus 10. After storing thetotal weight of the patient support apparatus 10, the routine process100 advances to step 400 to determine and offset the tare weight.

Referring to FIG. 17, at decision step 402, the controller 86 determineswhether a historical tare weight data exists. For example, in oneembodiment, the controller 86 determines whether the historical tareweight data corresponding to the patient support apparatus 10 exists. Ifthe controller 86 determines that the historical tare weight data forthe patient support apparatus 10 exists, then the routine process 100advances to step 406 in which the controller 86 recalls the historicaltare weight data. However, if the controller 86 instead determines atdecision step 402 that the historical tare weight data for the patientsupport apparatus 10 does not exist, then the routine process 100advances to step 404 in which the controller 86 recalls the initial tareweight data from step 300.

After determining the initial or historical tare weight in step 404 or406, respectively, the detectors 50 detect and the controller 86recognizes which removable components 14 was added or removed from thepatient support apparatus 10. If the detectors 50 detect any removablecomponents 14 added on the patient support apparatus 10 at decision step408, the controller 86 adds the predetermined weights of the addedremovable components 14 to the initial or historical tare weight. If,however, the detectors 50 detect any removable components 14 removedfrom the patient support apparatus 10 at decision step 412, thecontroller 86 subtracts the predetermined weights of the removedremovable components 14 from the initial or historical tare weight.Accordingly, at step 500, the controller 86 updates the initial orhistorical tare weight as a function of the historical tare weight data.

Referring to FIG. 18, at decision step 502, the controller 86 determineswhether a historical tare weight data exists. For example, in oneembodiment, the controller 86 determines whether the historical tareweight data corresponding to the patient support apparatus 10 exists. Ifthe controller 86 determines that the historical tare weight data forthe patient support apparatus 10 exists, then the process 100 advancesto step 506 in which the controller 86 update the existing historicaltare weight data. However, if the controller 86 instead determines atdecision step 502 that the historical tare weight data for the patientsupport apparatus 10 does not exist, then the process 500 advances tostep 504 in which the controller 86 update the new tare weight as afunction of historical tare weight data.

After updating and storing the tare weight of the current patientsupport apparatus 10 at step 500, the routine process 100 proceeds tostep 110 to determine the true patient weight. At step 110, thecontroller 86 determines the true weight of patient that is solelyattributable to the patient by offsetting the updated tare weight fromthe total amount of weight on the patient support apparatus 10.

Although certain illustrative embodiments have been described in detailabove, variations and modifications exist within the scope and spirit ofthis disclosure as described and as defined in the following claims.

The invention claimed is:
 1. A patient support apparatus having aplurality of removable components, the patient support apparatuscomprising a patient support, a plurality of load cells supporting thepatient support, each load cell configured to produce a signalindicative of an amount of weight on that load cell, a plurality ofdetectors, each detector associated with a particular one of theplurality of removable components to produce a signal indicative of apresence or absence of the corresponding removable component, and acontroller in communication with the plurality of the load cells and theplurality of detectors, the controller configured to: obtain the weightof each of the removable components of the patient support apparatus;receive the signal produced by each of the load cells and the detectors,determine a weight of the patient being supported on the patient supportcompensating for the presence or absence of each removable component,detect, subsequent to determining the weight of the patient, anysubsequent removal or addition of any of the plurality of removablecomponents of the patient support apparatus based on the signalsproduced by the plurality of detectors, and update the weight of thepatient being supported on the patient support considering the effect ofthe removal or addition of the removable components.
 2. The patientsupport apparatus of claim 1, wherein the controller is furtherconfigured to: determine an initial tare weight of the empty patientsupport apparatus, and determine whether the patient support issupporting a patient as a function of the signals produced by theplurality of load cells.
 3. The patient support apparatus of claim 2,wherein to determine whether the patient support is supporting thepatient comprises determining a current occupancy state of the patientsupport apparatus, wherein the current occupancy state of the patientsupport apparatus comprises at least one of an occupied state and anunoccupied state, the occupied state being indicated when the patientsupport is determined to be supporting the patient and the unoccupiedstate being indicated when the patient support is determined not to besupporting the patient.
 4. The patient support apparatus of claim 2,wherein the controller is further configured to: automatically updatethe tare weight of the patient support apparatus.
 5. The patient supportapparatus of claim 2, wherein the tare weight of the patient supportapparatus comprises the total amount of weight of the empty patientsupport apparatus being compensated for a first amount of weight andsecond amount of weight, the first amount of weight corresponding to theweight of the subsequently added removable components, and the secondamount of weight corresponding to the weight of the subsequently removedremovable components of the patient support apparatus.
 6. The patientsupport apparatus of claim 5, wherein updating the tare weight inresponse to detecting the addition or removal of the removablecomponents comprises updating the tare weight in response to (i)determining that the patient support is no longer supporting thepatient, (ii) storing the removable components initially detected on theempty patient support apparatus, (iii) storing total weight of the emptypatient support apparatus as a function of initial tare weight, and (iv)updating the tare weight by supplementing the weight of the removablecomponents added to the patient support apparatus or by offsetting theweight of the removable components removed from the patient supportapparatus in response to signals received from the plurality ofdetectors.
 7. The patient support apparatus of claim 2, wherein updatinga weight of the patient includes (i) determining the weight of the emptypatient support apparatus as a function of signals received from theplurality of load cells, (ii) determining the presence or absence ofremovable components of the patient support apparatus in response to thesignals received from the plurality of detectors, (iii) determining thetare weight of the patient support apparatus, and (iv) offsetting theupdated tare weight from the total amount of weight of the patientsupport apparatus.
 8. The patient support apparatus of claim 1, whereinthe controller is further configured to: determine a normalized amountof weight of each removable component of the patient support apparatusas a function of the signals produced by the plurality of load cells,detect the removable components currently attached to the patientsupport apparatus in response to detecting a presence or absence of thecorresponding removable component by the plurality of detectors,determine and store a total weight of the removable components currentlyattached to the patient support apparatus, and detect any subsequentaddition or removal of the removable components from the patient supportapparatus.
 9. The patient support apparatus of claim 1, wherein thecontroller is further configured to: set an initial occupancy state ofthe patient support apparatus to an unoccupied state, determine anormalized amount of weight on the plurality of load cells as a functionof the signals produced by the plurality of load cells, set the currentoccupancy state of the patient support apparatus to the occupied statein response to the normalized amount of weight on the plurality of loadcells satisfying an occupied condition, the occupied condition defininga first normalized threshold value for which the normalized amount ofweight on the plurality of load cells must exceed, and set the currentoccupancy state of the patient support apparatus to the unoccupied statein response to the normalized amount of weight on the plurality of loadcells satisfying an unoccupied condition, the unoccupied conditiondefining a second normalized threshold value for which the normalizedamount of weight on the plurality of load cells must be below.
 10. Thepatient support apparatus of claim 9, wherein the controller is furtherconfigured to determine, in response to determining that the patientsupport is no longer supporting the patient, a total amount of weight ofthe empty patient support apparatus as a function of signals receivedfrom the plurality of load cells, and set and store the total amount ofweight of the empty patient support apparatus as an initial tare weightof the patient support apparatus.
 11. The patient support apparatus ofclaim 10, wherein the total amount of weight of the empty patientsupport apparatus comprises the amount of weight on the plurality ofload cells of the empty patient support apparatus, wherein the amount ofweight of the empty patient support apparatus includes the total amountof weight of the removable components currently attached to the emptypatient support apparatus.
 12. The patient support apparatus of claim 1,wherein the controller comprises a processor; and at least onemachine-readable storage medium comprising a plurality of instructions,that in response to being executed by the processor, automaticallydetermine the patient weight based on the signals from the load cellsand the sensors.
 13. The patient support apparatus of claim 12, whereindetermining the presence or absence of removable components of thepatient support apparatus comprises detecting the signal produced by oneor more corresponding detectors associated with each removablecomponent.
 14. The patient support apparatus of claim 13, wherein theremovable component of the patient support apparatus includes headboard,footboard, siderail, infusion support, drainage container, or urinalcontainer.
 15. The patient support apparatus of claim 14, wherein thepatient support apparatus further comprises a user interface thatincludes a graphical display and the presence or absence of any one ofthe removable components is indicated by an icon representation of thepatient support apparatus.
 16. The patient support apparatus of claim15, wherein the information regarding the presence or absence ofremovable components is transmitted to a graphical display remote fromthe patient support apparatus.
 17. The patient support apparatus ofclaim 16, wherein the remote graphical display is a mobile computingdevice associated with a particular caregiver.